1. Field of the Invention
The invention relates to an apparatus and process for forming an opening through conduit located in a borehole formed in the earth.
2. Description of the Related Art
U.S. Pat. Nos. 4,298,063, 4,598,769, and 5,435,394 disclose apparatus for cutting conduit located in a borehole formed in the earth. U.S. Pat. Nos. 4,598,769 and 5,435,394 are incorporated into this application by reference.
It is an object of the invention to provide a new and useful apparatus and process for cutting an opening in a conduit located in a borehole formed in the earth.
The apparatus of the invention comprises a body adapted to be lowered into the casing located in the borehole. The body comprises a surrounding wall defining an elongated chamber having a combustible charge receiving portion and an ignition system, or ignition means portion located close to the combustible charge receiving portion. A portion of the wall surrounding the combustible charge receiving portion has a plurality of spaced apart apertures formed therethrough in a given pattern. A combustible charge is located in the combustible charge receiving portion of the chamber. An ignition means is located in the ignition means portion of the chamber for igniting the combustible charge for creating a flame and hot combustion products for passage through the apertures for cutting an opening in the surrounding conduit.
The opening may be formed by burning an enlarged area through the conduit or by burning a slot through the conduit around a conduit wall portion which wall portion then is removed.
In the preferred embodiment, the combustible charges are located above, at the level of and below the apertures.